Hydrogel implants with porous materials and methods

ABSTRACT

Provided is an implant configured for implantation in a bone segment, the implant including a first part that includes a hydrogel portion and a porous material portion, and a second part that includes an annular rim and a bottom that at least partially define a cavity configured to receive the porous material portion of the first part, and a barb extending from the bottom of the second part in a direction away from the cavity.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 17/197,595, filed Mar. 10, 2021, which is a continuation ofU.S. patent application Ser. No. 15/909,077, filed Mar. 1, 2018 andissued as U.S. Pat. No. 10,973,644, which is a continuation of U.S.patent application Ser. No. 15/085,840, filed Mar. 30, 2016 and issuedas U.S. Pat. No. 9,907,663, which claims priority benefit of U.S.Provisional Patent App. No. 62/141,059, filed on Mar. 31, 2015.

BACKGROUND Field

This disclosure relates generally to implants, and, more specifically,to hydrogel joint implants and various tools, devices, systems, andmethods related thereto.

Description of Related Art

Implants can be used to replace deteriorated or otherwise damagedcartilage within a joint. Such devices can be used to treatosteoarthritis, rheumatoid arthritis, other inflammatory diseases,generalized joint pain, joints damaged in an accident, while damagedparticipating in athletics, joints damaged due to repetitive use, and/orother joint diseases.

SUMMARY

In some embodiments, an implant configured for implantation in a jointcomprises, or alternatively consists essentially of, a first portion, asecond portion, and a third portion. The first portion comprises ahydrogel. The second portion comprises a porous material (e.g., ceramic,metal, plastic) and the hydrogel in pores of the porous material. Thethird portion comprises the porous material. The second portion isbetween the first portion and the second portion. The first portion isfree or substantially free of the porous material. The third portion isfree or substantially free of the hydrogel.

The hydrogel may comprise polyvinyl alcohol (PVA). The hydrogel maycomprise water. The hydrogel may comprise saline. The porous materialmay comprise an oxide material. The porous material may comprise atleast one of aluminum, alumina, zirconia, titanium, titania, stainlesssteel, PEEK, and steatite. The porous material may have a porositybetween 45 ppi and 80 ppi. Pores of the porous material may have adimension between 100 μm and 500 μm. The first portion may comprise acontoured surface. The first portion may comprise an annular flange. Thethird portion may comprise threads. The implant may be load bearing andnon-biodegradable. The implant may be configured to be placed in atleast one of a toe, finger, ankle, knee, shoulder, hip, or other joint.A lateral dimension of the first portion may be between 6 mm and 10 mm.A lateral dimension of the first portion may be between 5% and 15%larger than a lateral dimension of the third portion. A ratio of alateral dimension of the first portion to a lateral dimension of thethird portion may be between 1.05 and 1.3.

In some embodiments, a method of treatment comprises, or alternativelyconsists essentially of, aligning an implant deployment tool with arecess in a bone, the recess comprising an opening facing a joint, anddeploying the implant out of the implant deployment tool, through theopening, and at least partially in the recess

After deployment, the implant may be 1 mm to 3 mm proud. The method mayfurther comprise radially compressing the first portion of the implantin the implant deployment tool. The method may further comprise formingthe recess. Forming the recess may comprise using a drill bit. Deployingthe implant may comprise urging the implant through an interior of theimplant deployment tool using a plunger. Deploying the implant may bemanual. Deploying the implant may be mechanically assisted. Deployingthe implant may comprise screwing the implant into the recess.

In some embodiments, a method of manufacturing the implant comprises, oralternatively consists essentially of, positioning hydrogel material ina well of a mold, positioning porous material in an upper portion of thewell and protruding from the well, and freezing and thawing the hydrogelmaterial at least once.

Positioning the porous material may comprise anchoring the porousmaterial.

In some embodiments, a method of manufacturing the implant comprises, oralternatively consists essentially of, aligning a well of a second moldportion with a well of a first mold portion, the well of the first moldportion comprising a porous material, positioning hydrogel material inthe well of the second mold portion and partially in the well of thefirst mold portion, and freezing and thawing the hydrogel material atleast once.

The method may further comprise positioning the porous material in thewell of the first mold portion. Positioning the hydrogel material may bethrough a closable port, and further comprising closing the closableport. The method may comprising forming flash between the first moldportion and the second mold portion. The method may further compriseremoving the flash. The porous material may comprise a disc shape.

In some embodiments, an implant system configured for implantation in ajoint comprises, or alternatively consists essentially of, a first partand a second part. The first part comprises an implant. The implantcomprises, or alternatively consists essentially of, a first portioncomprising a hydrogel, a second portion comprising a porous material andthe hydrogel in pores of the porous material, and a third portioncomprising the porous material. The first portion is free of or lacksthe porous material. The third portion is free of or lacks the hydrogel.The second part comprises sidewalls, a bottom, a cavity at leastpartially defined by the sidewalls and the bottom, and an anchoringelement. The cavity is configured to at least partially receive theimplant. One of the porous material and the sidewalls of the second partcomprises a detent and the other of the porous material and thesidewalls of the second part comprises a groove configured to interactwith the detent when the implant is at least partially in the cavity ofthe second part.

The porous material may comprise a toroidal shape. The porous materialmay comprise a detent extending radially inward. The anchoring elementmay selected from the group consisting of a barb, and anchor, and a holein the bottom of the second part and a screw configured to extendthrough the hole in the bottom of the second part. The anchor maycomprise an insert, a finger extending radially outwardly and towards atop of the implant system, a wire threaded through holes in the bottomof the second part, and a knot configured to be tightened upon pullingof ends of the wire.

In some embodiments, an implant system configured for implantation in ajoint comprises, or alternatively consists essentially of, a first partand a second part. The first part comprises an implant comprising afirst portion comprising a hydrogel, a second portion comprising aporous material and the hydrogel in pores of the porous material, and athird portion comprising the porous material. The first portion is freeof or lacks the porous material. The third portion is free of or lacksthe hydrogel. The second part comprises sidewalls, a bottom, and acavity at least partially defined by the sidewalls and the bottom. Thecavity is configured to at least partially receive the implant.

One of the porous material and the sidewalls of the second part maycomprise a detent and the other of the porous material and the sidewallsof the second part may comprise a groove configured to interact with thedetent when the implant is at least partially in the cavity of thesecond part. The second part may further comprise an anchoring element.The anchoring element may comprise a barb. The anchoring element maycomprise an anchor comprising an insert, a finger extending radiallyoutwardly and towards a top of the implant system, a wire threadedthrough holes in the bottom of the second part, and a knot configured tobe tightened upon pulling of ends of the wire. The ends of the wire mayform a loop. The anchoring element may comprise a hole in the bottom ofthe second part and a screw configured to extend through the hole in thebottom of the second part. The anchoring element may comprise a hole inthe sidewalls of the second part and a second screw configured to extendthrough the hole in the sidewalls of the second part.

In some embodiments, an implant system configured for implantation in ajoint comprises a first portion comprising a hydrogel, a second portioncomprising a porous material and the hydrogel in pores of the porousmaterial, and a third portion comprising the porous material. The firstportion is free of or lacks the porous material. The third portion isfree of or lacks the hydrogel. The third portion is configured tocontact bone. Pores of the porous material are configured to allow boneinfiltration.

The first portion may comprise a contoured surface. The contouredsurface may be customized for a particular subject based on scan data.The scan data may comprise at least one of computerized tomography,computerized axial tomography, positron emission tomography, andmagnetic resonance imaging. The porous material may comprise at leastone of aluminum, titanium, and stainless steel. The porous material maycomprise titanium mesh. The porous material may comprise printedtitanium. The porous material may comprise at least one of alumina,zirconia, titania, and steatite. The porous material may comprise PEEK.The porous material may have a porosity between 45 ppi and 80 ppi. Poresof the porous material may have a dimension between 100 μm and 500 μm.The first portion may comprise a hemispherical shape. The first portionmay comprise a wedge shape.

In some embodiments, an implant system configured for implantation in ajoint comprises an implant comprising a first portion comprising ahydrogel, a second portion comprising a porous material and the hydrogelin pores of the porous material, and a third portion comprising theporous material. The first portion is free of or lacks the porousmaterial. The third portion is free of or lacks the hydrogel.

The second portion may be between the first portion and the secondportion. The hydrogel may comprise polyvinyl alcohol (PVA). The hydrogelmay comprise water. The hydrogel may comprise saline. The porousmaterial may comprise an oxide ceramic. The porous material may compriseat least one of aluminum, titanium, and stainless steel. The porousmaterial may comprise titanium mesh. The porous material may compriseprinted titanium. The porous material may comprise PEEK. The porousmaterial may comprise at least one of alumina, zirconia, titania, andsteatite. The porous material may have a porosity between 45 ppi and 80ppi. Pores of the porous material may have a dimension between 100 μmand 500 μm. The first portion may comprise an annular flange. The thirdportion may comprise threads.

The first portion may comprise a contoured surface. The contouredsurface may be customized for a particular subject based on scan data.The scan data may comprise at least one of computerized tomography,computerized axial tomography, positron emission tomography, andmagnetic resonance imaging.

The first portion may comprise a hemispherical shape. The second portionmay comprise a hemispherical shape. The third portion may comprise acylindrical shape. The first portion may comprise a wedge shape. Thethird portion may comprise a wedge shape. The porous material maycomprise a disc shape. The porous material may comprise a toroidalshape. The porous material may comprise a detent extending radiallyinward. The porous material may comprise an aperture through a sidewallof the porous material. The hydrogel may at least partially extendthrough the aperture. The porous material may comprise a fingerextending radially outwardly and towards a top of the implant system.The porous material may comprise a barb.

The implant may be load bearing. The implant may be non-biodegradable.The implant system may be configured to be placed in at least one of atoe, finger, ankle, knee, shoulder, hip, or other joint. A lateraldimension of the first portion may be between 6 mm and 10 mm. A lateraldimension of the first portion may be between 5% and 15% larger than alateral dimension of the third portion. A ratio of a lateral dimensionof the first portion to a lateral dimension of the third portion may bebetween 1.05 and 1.3.

The implant system may further comprise a second part comprisingsidewalls, a bottom, and a cavity at least partially defined by thesidewalls and the bottom. The cavity may be configured to at leastpartially receive the implant. The porous material may comprise a grooveextending radially inward and the second part may comprise a detentextending radially inward from the sidewalls of the second part. Thedetent may be configured to interact with the groove when the implant isat least partially in the cavity of the second part. The porous materialmay comprise a detent extending radially outward and the second part maycomprise a groove extending radially outward into the sidewalls of thesecond part. The detent may be configured to interact with the groovewhen the implant is at least partially in the cavity of the second part.

The second part further may comprise an anchoring element. The anchoringelement may comprise a barb. The barb may comprise a plurality of barbs.The plurality of barbs may be vertically stacked. The anchoring elementmay comprise an anchor comprising an insert, a finger extending radiallyoutwardly and towards a top of the implant system, a wire threadedthrough holes in the bottom of the second part, and a knot configured tobe tightened upon pulling of ends of the wire. The ends of the wire mayform a loop. The anchoring element may comprise a hole in the bottom ofthe second part and a screw configured to extend through the hole in thebottom of the second part. The anchoring element may comprises aplurality of holes in the bottom of the second part and a plurality ofscrews configured to extend through the plurality of holes in the bottomof the second part. The anchoring element may comprise a hole in thesidewalls of the second part and a second screw configured to extendthrough the hole in the sidewalls of the second part. The anchoringelement may comprise a plurality of holes in the sidewalls of the secondpart and a plurality of second screws configured to extend through theplurality of holes in the sidewalls of the second part.

In some embodiments, a method of treatment comprises, or alternativelyconsists essentially of, aligning an implant deployment tool with arecess in a bone and deploying the implant out of the implant deploymenttool, through the opening, and at least partially in the recess. Therecess comprises an opening facing a joint.

After deployment, the implant may be 1 mm to 3 mm proud. The method mayfurther comprise radially compressing the first portion of the implantin the implant deployment tool. The method may further comprise formingthe recess. Forming the recess may comprise using a drill bit. Deployingthe implant may comprise urging the implant through an interior of theimplant deployment tool using a plunger. Deploying the implant may bemanual. Deploying the implant may be mechanically assisted. Deployingthe implant may comprise screwing the implant into the recess.

In some embodiments, a method of manufacturing the implant comprisespositioning hydrogel material in a well of a mold, positioning porousmaterial in an upper portion of the well and protruding from the well,and freezing and thawing the hydrogel material at least once.Positioning the porous material may comprise anchoring the porousmaterial.

In some embodiments, a method of manufacturing the implant comprisesaligning a well of a second mold portion with a well of a first moldportion. The well of the first mold portion comprises a porous material.The method further comprises positioning hydrogel material in the wellof the second mold portion and partially in the well of the first moldportion and freezing and thawing the hydrogel material at least once.The method may further comprising positioning the porous material in thewell of the first mold portion. Positioning the hydrogel material may bethrough a closable port. The method may further comprise closing theclosable port.

The method may comprising forming flash between the first mold portionand the second mold portion. The method may further comprise removingthe flash. The porous material may comprises a disc shape. The porousmaterial may comprises a toroidal shape.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain features, aspects, and advantages of the disclosure aredescribed with reference to drawings, which are intended to illustrate,but not to limit, the various inventions disclosed herein. It is to beunderstood that the attached drawings are for the purpose ofillustrating concepts and embodiments of the disclosure and may not beto scale.

FIG. 1A schematically illustrates an example implant;

FIG. 1B schematically illustrates an example implant;

FIG. 1C schematically illustrates an example implant;

FIG. 2 is a photo of an example implant;

FIGS. 3A and 3B schematically illustrate an example method ofpositioning an example implant;

FIG. 3C schematically illustrates an example method of positioning theexample implant of FIG. 1B;

FIG. 4 schematically illustrates an example method of manufacturingexample implants;

FIGS. 5A-5C schematically illustrate an example method of manufacturingexample implants;

FIG. 6 schematically illustrates another example implant

FIG. 7A schematically illustrates an example implant;

FIG. 7B schematically illustrates an example method of positioning anexample implant;

FIG. 7C schematically illustrates an example method of positioning anexample implant;

FIG. 8A schematically illustrates an example implant;

FIG. 8B schematically illustrates an example method of positioning anexample implant;

FIG. 8C schematically illustrates an example method of positioning anexample implant;

FIG. 9A is a side view of an example implant;

FIG. 9B is a cross-sectional view of the implant of FIG. 9A;

FIGS. 9C and 9D are top and side perspective exploded views of theimplant of FIG. 9A;

FIG. 9E is a cross-sectional view of an example implant;

FIG. 10A is a side view of an example implant;

FIG. 10B is a cross-sectional view of the implant of FIG. 10A;

FIGS. 10C-10E are top and side perspective exploded views of the implantof FIG. 10A;

FIG. 10F is a cross-sectional view of an example implant;

FIG. 11A is a side view of an example implant;

FIG. 11B is a cross-sectional view of the implant of FIG. 11A;

FIG. 11C is a top and side perspective view of the implant of FIG. 11A;

FIG. 11D is a top and side perspective exploded view of the implant ofFIG. 11A;

FIG. 11E is a cross-sectional view of an example implant;

FIG. 12A is a side cross-sectional view of an example implant;

FIG. 12B is a side cross-sectional view of an example implant;

FIG. 12C is a side cross-sectional view of an example implant;

FIG. 12D is a side cross-sectional view of example implants;

FIG. 13A is a top and side perspective view of an example implant; and

FIG. 13B is plan view of an example device for manufacturing exampleimplants.

DETAILED DESCRIPTION

The discussion and the figures illustrated and referenced hereindescribe various embodiments of a cartilage implant, as well as varioustools, systems, and methods related thereto. A number of these devicesand associated treatment methods are particularly well suited to replacedeteriorated or otherwise damaged cartilage within a joint. Suchimplants are configured to remain within the patient's joint on along-term basis (e.g., for most or all of the life of the patient orsubject), and as such, are configured, in some embodiments, to replacenative cartilage. In some embodiments, an implant is configured to besubstantially non-biodegradable and/or non-erodable. In someembodiments, an implant is configured to remain within the patient'sjoint or other portion of the anatomy for a minimum of 10 to 100 years(e.g., about 10 years, about 20 years, about 25 years, about 30 years,about 35 years, about 40 years, about 45 years, about 50 years, about 55years, about 60 years, about 65 years, about 70 years, about 75 years,about 80 years, about 85 years, about 90 years, about 95 years, about100 years, duration ranges between the foregoing values, etc.) withoutlosing structural and/or physical properties and/or without losingability to function as a cartilage replacement component or device. Insome embodiments, an implant is configured to remain within the anatomyfor greater than 100 years without losing structural and/or physicalproperties and/or without losing ability to function as a cartilagereplacement component. Certain implants described herein can be used totreat osteoarthritis, rheumatoid arthritis, other inflammatory diseases,generalized joint pain, joints damaged in an accident, joints damagedwhile participating in athletics, joints damaged due to repetitive use,and/or other joint diseases. However, the various devices, systems,methods, and other features of the embodiments disclosed herein may beutilized or applied to other types of apparatuses, systems, procedures,and/or methods, including arrangements that have non-medical benefits orapplications.

Certain embodiments described herein may be advantageous because theyinclude one, several, or all of the following benefits: (i) improvedosseointegration compared to implants having a hydrogel surface; (ii)improved coupling of disparate implant materials; (iii) improved cavitywall apposition compared to substantially cylindrical implants; (iv)reduced implant height; (v) reduced depth of a bone cavity configured toreceive an implant; (vi) improved structural stability; and/or (vii)increased manufacturing flexibility.

FIG. 1A schematically illustrates an example implant 100. The implant100 comprises, or alternatively consists essentially of, a first portion102, a second portion 104, and a third portion 106. The first portion102 and the second portion 104 of the implant 100, as well as otherimplants disclosed herein (as is the case for each implant featureunless described otherwise), comprises, or alternatively consistsessentially of, a hydrogel (e.g., a hydrogel or other formulationcomprising polyvinyl alcohol (PVA) hydrogel). The third portion 106comprises, or alternatively consists essentially of, a porous material(e.g., a material or section comprising porous ceramic material (e.g.,oxide-ceramic), metal (e.g., titanium (e.g., titanium mesh, printedtitanium), stainless steel (e.g., stainless steel wool)), plastic (e.g.,polyaryl ether ketone (PAEK) (e.g., polyether ether ketone (PEEK))),other biocompatible materials, combinations thereof, and the like).

The first portion 102 and the second portion 104 of the implant 100 cancomprise one or more other materials, either in addition to or in lieuof PVA, such as, for example, other hydrogels, other polymericmaterials, additives, and/or the like. As discussed herein, the secondportion 104 comprises porous material. In some embodiments, the PVAcontent of a hydrogel is about 40% by weight. The PVA content ofhydrogel in an implant 100 can be less than or more than about 40% byweight (e.g., about 10%, about 15%, about 20%, about 25%, about 30%,about 32%, about 34%, about 36%, about 37%, about 38%, about 39%, about41%, about 42%, about 43%, about 44%, about 46%, about 48%, about 50%,about 55%, about 60%, about 65%, about 70%, less than about 10%, morethan about 70%, ranges between such values, etc.), as desired orrequired.

The hydrogel of the implant 100, as well as other implants disclosedherein, can comprise water, saline, other liquids, combinations thereof,and/or the like. In some embodiments, saline may be preferred overwater, because, under certain circumstances, saline can help maintainosmotic balance with surrounding anatomical tissues followingimplantation. The exact composition of hydrogel in an implant 100 (e.g.,PVA or other hydrogel materials, water, saline or other liquids, otheradditives, etc.) can be selected so as to provide the implant 100 withthe desired or required strength, load bearing capacity,compressibility, flexibility, longevity, durability, resilience,coefficient of friction, and/or other properties and characteristics.Thus, in some embodiments, any hydrogel portion of the implantsdisclosed herein consist essentially of saline and PVA. In someembodiments, such hydrogel portions of the implants do not comprise anyadditional additives (e.g., growth factors, surface or other coatings,etc.). In addition, according to some embodiments, the hydrogel portionsof any of the implant configurations disclosed herein comprises aconsistent concentration (e.g., no concentration gradients), densityand/or other chemical and/or physical properties throughout.

In some embodiments, the implant 100, as well as other implantsdisclosed herein, is configured for drug delivery and/or is seeded withgrowth factors and/or cells. In some embodiments, the implant 100comprises one or more of the following: chondrocytes, growth factors,bone morphogenetic proteins, collagen, hyaluronic acid, nucleic acids,and stem cells. Such factors and/or any other materials included in theimplant 100 and selectively delivered to an implant site can helpfacilitate and/or promote the long-term fixation of the implant 100 atthe joint or other target area of the anatomy.

In some embodiments, the hydrogel comprises PVA and/or any otherpolymeric material. In some embodiments, the content of PVA in thehydrogel is between about 35% and about 45% by weight (e.g., about 35%,about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about42%, about 43%, about 44%, about 45%, ranges between such values, etc.).In some embodiments, the content of PVA in the hydrogel is greater thanabout 45% by weight (e.g., about 45%, about 50%, about 55%, about 60%,about 65%, about 70%, greater than about 70%, ranges between suchvalues, etc.) or less than about 35% by weight (e.g., about 5%, about10%, about 15%, about 20%, about 25%, about 30%, about 35%, rangesbetween such values, less than about 5%, etc.). In some embodiments, thecontent of PVA or other component in the hydrogel is about 40% byweight.

In some embodiments, the implant 100 is load bearing and generallynon-biodegradable (e.g., non-bioerodable). In some embodiments, theimplant 100 is configured for placement in at least one of a toe,finger, ankle, knee, shoulder, hip, or any other joint. In someembodiments, a transition between the upper surface and the sidewalls isgenerally curved or otherwise smooth.

In some embodiments, the first portion 102 of the implant may have alateral dimension (e.g., diameter) between about 6 mm and about 10 mm(e.g., about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm,ranges between such values, etc.), as measured in an uncompressed state.Lateral dimensions smaller than about 6 mm (e.g., between about 2 mm andabout 6 mm) and larger than about 10 mm (e.g., between about 10 mm andabout 14 mm) are also possible for use in subjects with small or largebones, respectively, and/or for use in joints with small or large bones,respectively.

The third portion 106 of the implant can comprise a porous material,such as, for example, a porous ceramic (e.g., oxide-ceramic), metal(e.g., titanium (e.g., titanium mesh, printed titanium), stainless steel(e.g., stainless steel wool)), plastic (e.g., polyaryl ether ketone(PAEK) (e.g., polyether ether ketone (PEEK))), other biocompatiblematerials, combinations thereof, and the like). The third portion 106may be free or substantially free from the hydrogel of the first portion102. In some embodiments, the third portion 106 is substantially rigidor non-deformable. In some embodiments, the third portion 106 is atleast partially deformable. The pores and/or other openings of the thirdportion 106 may promote osseointegration of the implant 100 in a bone.Compared to an implant consisting essentially of hydrogel, an implantcomprising one or more porous materials (e.g., porous ceramic, metal,plastic, etc.) may have a reduced height because the porous ceramicand/or other porous material may provide structural stability and/orbecause the porous ceramic or other porous material may provide betterosseointegration such that less contact with bone provides at least asmuch osseointegration.

The third portion 106 is illustrated in FIG. 1A as a disc, althoughother shapes of the third portion 106 are also possible. In someembodiments, the third portion 106 may be toroidal, wedge-shaped, etc.,for example as described in further detail herein. In some embodiments,the third portion 106 is substantially rigid, semi-rigid, and/ornon-deformable. In some embodiments, the second portion 104 comprisesthe hydrogel of the first portion 102 within pores of the porousmaterial of the third portion 106. According to some embodiments, thediameter or other lateral dimension of the second portion 104 and/orthird portion 106 is smaller than the diameter or other lateraldimension of the first portion 102 of the implant. As discussed herein,this can permit the implant 100 to be radially compressed (e.g., duringdelivery into a target anatomical site of a subject), especially inembodiments where the first portion 102 is more readily radiallycompressible than the second portion 104 and/or the third portion 106(e.g., because of the material(s) included in each portion). Forexample, in some embodiments, the diameter or other lateral dimension ofthe second portion 104 and/or third portion 106 is between about 70% andabout 95% (e.g., about 70%, about 75%, about 80%, about 85%, about 90%,about 95%, ranges between the foregoing percentages, etc.) of thediameter or other lateral dimension of the first portion 102.

According to some embodiments, the second portion 104 and the thirdportion 106 may comprise an oxide ceramic, for example oxide ceramicsfrom CeramTec of Laurens, South Carolina, as provided in Tables 1 and 2,although other materials and combinations of materials are also possible(e.g., non-oxide ceramics, non-ceramics).

TABLE 1 Alumina Alumina Alumina Alumina Alumina Property Units (92%)(94%) (96%) (99.5%) I (99.5%) II Density g/cm³ 3.65 3.6 3.7 3.9 3.9Hardness HV 0.5 1300 1200 1350 1700 1700 Flexural MPa   240 (34.8) 290(42) 296 (43) 310 (45) 310 (45) Strength (k PSI) Fracture MPa × m^(1/2)5 3 4 4 4 Toughness Young's GPa 300 (44) 289 (42) 303 (44) 372 (54) 376(54) Modulus (×10⁶ PSI) Shear GPa 120 (17)   121 (17.5)   127 (18.5) 152(22) 152 (22) Modulus (×10⁶ PSI) Polsson — 0.24 0.21 0.21 0.21 0.21Thermal ×10⁻⁶/° C. 7.0 6.6 6.5 6.8 6.7 Expansion (300° C.) Thermal×10⁻⁶/° C. 7.3 7.6 7.6 7.9 7.8 Expansion (700° C.) Thermal ×10⁻⁶/° C.7.5 8.2 8.1 8.3 8.2 Expansion (1,000° C.) Thermal W/mK 21.0 21.0 24.030.0 30.0 Conductivity at 25° C. Volume ohm × cm >10¹⁴ >10¹⁴ >10¹⁴ >10¹⁴>10¹⁴ Resistivity Specific J/gK 0.96 0.8 1.1 0.8 0.8 Heat DielectricV/mil — 200 210 230 220 Strength Dielectric — — 9.0 9.3 9.8 9.8 Constantat 1 MHz Dissipation — 9.0 × 10⁻⁴ 3.0 × 10⁻⁴ 3.0 × 10⁻⁴ 1.0 × 10⁻⁴ 1.0 ×10⁻⁴ Factor at 1 MHz Loss Factor — — 3.0 × 10⁻³ 3.0 × 10⁻³ 1.0 × 10⁻³1.0 × 10⁻³ at 1 MHz

TABLE 2 Toughened Steatite Steatite Property Units Alumina ZirconiaTitania I II Density g/cm³ 4.0 6.0 4.0 2.7 2.8 Hardness HV 0.5 1600 1150800 450 420 Flexural MPa 448 (65) 752 (109) 138 (20) 131 (19) 145 (21)Strength (k PSI) Fracture MPa × m^(1/2) 4 10 3 — — Toughness Young's GPa— 186 (27)  227 (33) 108 (16) 112 (16) Modulus (×10⁶ PSI) Shear GPa —  80 (11.6)   90 (13.0)   43 (6.3)   45 (6.5) Modulus (×10⁶ PSI) Polsson— — 0.33 0.27 0.23 0.25 Thermal ×10⁻⁶/° C. 7.9 — 8.3 8.2 6.9 Expansion(300° C.) Thermal ×10⁻⁶/° C. 8.5 10.0 9.0 8.9 7.8 Expansion (700° C.)Thermal ×10⁻⁶/° C. 9.6 11.0 9.0 9.4 8.0 Expansion (1,000° C.) ThermalW/mK 25.0 2.7 11.9 5.5 5.9 Conductivity at 25° C. Volume ohm × cm 9.0 ×10¹³ — >10¹² >10¹⁴ >10¹⁴ Resistivity Specific J/gK 0.96 0.4 0.7 1.1 1.1Heat Dielectric V/mil — — 100 210 230 Strength Dielectric — — 28 85 5.86.1 Constant at 1 MHz Dissipation — 9.0 × 10⁻⁴ — 5.0 × 10⁻⁴ 1.9 × 10⁻³8.0 × 10⁻⁴ Factor at 1 MHz Loss Factor — — — — 1.1 × 10⁻² 5.0 × 10⁻³ at1 MHz

According to some embodiments, the second portion 104 and the thirdportion 106 may comprise a metal, for example titanium mesh, printedtitanium, stainless steel, etc. According to some embodiments, thesecond portion 104 and the third portion 106 may comprise a plastic, forexample PAEK, PEEK, etc.

In some embodiments, the porous material can have a porosity betweenabout 45 pores per inch (ppi) and about 80 ppi (e.g., about 45 ppi,about 50 ppi, about 55 ppi, about 60 ppi, about 65 ppi, about 70 ppi,about 75 ppi, about 80 ppi, ranges between such values, etc.). The poresof the porous material may have a diameter or other dimension betweenabout 100 micrometers (microns; μm) and about 500 μm (e.g., about 100μm, about 150 μm, about 200 μm, about 250 μm, about 300 μm, about 350μm, about 400 μm, about 450 μm, about 500 μm, ranges between suchvalues, etc.), as desired or required.

In some embodiments, pores of the porous material in the second portion104 are different than pores of the porous material in the third portion106. For example, the pores of the porous material in the second portion104 may be configured to allow hydrogel infiltration while the pores ofthe porous material in the third portion 106 may be configured to allowosseointegration. In some embodiments, the porous material in the secondportion 104 is different than the porous material in the third portion106. For example, the porous material in the second portion 104 maycomprise a first material having a property and the porous material inthe third portion 106 may comprise a second material having a propertydifferent than the property of the first material. The property maycomprise, for example, the material itself (e.g., whether ceramic,metal, plastic, etc.), porosity, pore size, dimensions, deformability,etc.

Overlap of hydrogel material of the first portion 102 and porousmaterial of the third portion 106 in the second portion 104, for exampleby the hydrogel material filling pores of the porous material, maysecurely anchor the first portion 102 to the third portion 106, forexample compared to an implant in which a surface of a hydrogel materialis adhered to a surface of another material. In some embodiments, aratio of a height of the second portion 104 to a height of the thirdportion 106 is between about 1:5 and about 5:1 (e.g., about 1:5, about1:4, about 1:3, about 1:2, about 1:1, about 2:1, about 3:1, about 4:1,about 5:1, ranges between such values, etc.). In some embodiments, aratio of a height of the second portion 104 to a height of the ceramicmaterial (e.g., a height of the second portion 104 and a height of thethird portion 106) is between about 1:5 and about 1:1.1 (e.g., about1:5, about 1:4, about 1:3, about 1:2, about 1:1.5, about 1:1.4, about1:1.3, about 1:1.2, about 1:1.1, ranges between such values, etc.). Insome embodiments, a ratio of a height of the third portion 106 to aheight of the ceramic material (e.g., a height of the second portion 104and a height of the third portion 106) is between about 1:5 and about1:1.1 (e.g., about 1:5, about 1:4, about 1:3, about 1:2, about 1:1.5,about 1:1.4, about 1:1.3, about 1:1.2, about 1:1.1, ranges between suchvalues, etc.).

Compared to an implant consisting essentially of hydrogel, an implantcomprising porous material (e.g., porous ceramic, metal, plastic, etc.)may have a reduced height. For example, compared to implants consistingonly or essentially of a hydrogel material, such hybrid implants canhave a height that is reduced by between about 5% and about 30% (e.g.,about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, rangesbetween the foregoing percentages, etc.). In some embodiments, the thirdportion 106 of the implant 100 may provide improved or enhancedstructural stability to the implant 100. Such improved or enhancedstructural stability may be beneficial for use with large bones,although use with small bones is also possible.

Although the implant 100 is schematically illustrated as a cylindricalplug, other shapes of the implant 100 are also possible. For example, anupper surface of the first portion 102 may be contoured to abutparticular anatomy (e.g., planar (e.g., flat), non-planar (e.g., curved,concave, convex, undulating, fluted)). The implant 100 can include agenerally circular or oval cross-sectional shape. In some embodiments,the implant 100 is generally shaped like a cylinder or a mushroom. Theoverall shape of any of the implants disclosed herein can vary dependingon the specific application or use. For example, the shape of at leastpart of a portion 102, 104, 106 can be generally polygonal (e.g.,rectangular, round, hexagonal), irregular, and/or the like.

A molding process, for example as described herein with respect to FIGS.4 and/or with respect to FIGS. 5A-5C, may be used to form particularshape of an implant 100.

In some embodiments, means for treating a joint (e.g., the implant 100)comprises, or alternatively consists essentially of, means for providinga lubricious surface (e.g., the first portion 102) and means forpromoting osseointegration (e.g., the third portion 106).

FIG. 1B schematically illustrates an example implant 150. The implant150 comprises, or alternatively consists essentially of, a first portion152, a second portion, and a third portion 156. The first portion 152and the second portion of the implant 150 comprises, or alternativelyconsists essentially of, a hydrogel (e.g., a hydrogel or otherformulation comprising PVA hydrogel). The second portion is notillustrated due to the opacity of the hydrogel material of the firstportion 152. The third portion 156 comprises, or alternatively consistsessentially of, a porous material (e.g., a material or sectioncomprising porous ceramic material (e.g., oxide-ceramic), metal (e.g.,titanium (e.g., titanium mesh, printed titanium), stainless steel (e.g.,stainless steel wool)), plastic (e.g., polyaryl ether ketone (PAEK)(e.g., polyether ether ketone (PEEK))), other biocompatible materials,combinations thereof, and the like). The first portion 152, or thehydrogel material, comprises a contoured upper surface 162. The uppersurface 162 may be rounded at the edges and then flat (e.g., asillustrated in FIG. 1B), contoured to correspond to an opposing surface,etc. The hydrogel material of the implant 150 also includes a taper 164towards the porous material of the third portion 156. Other shapes,surface contours, and combinations thereof are also possible.

FIG. 1C schematically illustrates an example implant 180. The implant180 comprises, or alternatively consists essentially of, a first portion182, a second portion 184, and a third portion 186. The third portion186 comprises threads 188, which can allow the implant to be screwedinto bone and/or a hole in bone. The implant 180 may take the shape of ascrew. The threads 188 may comprise a same material as the third portion186 (e.g., porous material) or a different material than the thirdportion 186 (e.g., a non-porous ceramic, metal, plastic, etc.). Aspectsof orthopedic screws, dental implants, etc. such as coatings, surfacefeatures, etc. may be integrated into the threads 188 and/or the thirdportion 186. In some embodiments, the second portion 184 may comprisethreads. Threads in the second portion 184 may help, for example, toanchor the hydrogel material to the porous material and/or inhibitrelative longitudinal movement therebetween. Threads of the secondportion 184 may be the same or different than the threads 188 of thethird portion 186.

FIG. 2 illustrates one embodiment of an implant 200 comprising ahydrogel section and a porous material section. Similar to the implant100 discussed above, the illustrated implant 200 comprises a firsthydrogel portion 202, a second overlap portion 204, and a third porousmaterial portion 206. In the depicted arrangement, the third portion 206is substantially free from the hydrogel of the first portion 202, ashighlighted by the dotted line 208 between the second portion 204 andthe third portion 206. More or less overlap in the second portion 204 isalso possible, for example by using less hydrogel material and/or lessporous material, by adjusting height of the implant 200, etc. In someembodiments, a ratio of a height of the second portion 204 (e.g.,measured at an average of the hydrogel level) to a height of the implant200 is between about 5% and about 40% (e.g., about 5%, about 10%, about15%, about 20%, about 25%, about 30%, about 35%, about 40%, rangesbetween such values, etc.). In some embodiments, a ratio of a height ofthe second portion 204 to a height of the first portion 202 is betweenabout 15% and about 75% (e.g., about 15%, about 25%, about 35%, about45%, about 55%, about 65%, about 75%, ranges between such values, etc.).In some embodiments, a ratio of a height of the second portion 204 to aheight of the third portion 206 is between about 10% and about 90%(e.g., about 10%, about 20%, about 30%, about 40%, about 50%, about 60%,about 70%, about 80%, about 90%, ranges between such values, etc.).

FIGS. 3A and 3B schematically illustrate an example method ofpositioning an example implant 300. Similar to the implants 100, 200,the implant 300 comprises a first hydrogel portion 302, a second overlapportion 304, and a third porous material portion 306.

According to some embodiments, the bone portion 308 in which the implant300 will be positioned has been drilled to form a hole or aperture orrecess or cavity or crater or pit or pocket 310. In some embodiments,the lateral dimension (e.g., diameter) of the hole 310 is less than thelateral dimension (e.g., diameter) of the third portion 306, which isrigid. In some embodiments, a lateral dimension and/or cross-sectionalarea of the hole 310 is about 5% to about 15% (e.g., about 5%, about 6%,about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about13%, about 14%, about 15%, ranges between such values, etc.) wider orotherwise larger than the lateral dimension and/or cross-sectional areaof the third portion 306. The lateral dimension (e.g., diameter) of thehole 310 may be smaller than the lateral dimension (e.g., diameter) ofthe first portion 302, which may flex radially inwardly. Althoughillustrated as a cylindrical hole 310, other shapes are also possible(e.g., trapezoidal tapering inwards towards the upper surface). In someembodiments, a lateral dimension and/or cross-sectional area of the hole310 is about 5% to about 15% (e.g., about 5%, about 6%, about 7%, about8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%,about 15%, ranges between such values, etc.) narrower or otherwisesmaller than the lateral dimension and/or cross-sectional area of thefirst portion 302. The hole 310 may be coated or otherwise treated priorto positioning of the implant 300.

As a result of the shape of the implant 300 and the correspondingimplant site (e.g., in the hole 310), the implant 300 may be inwardlyradially compressed in order to insert the implant 300 in the hole 310.A delivery system or introducer 312 and/or other delivery tools can beused to facilitate positioning of the implant 300. Radially inwardcompressive forces may facilitate delivery of an implant 300 that is atleast partially radially oversized relative to the hole 310, asdiscussed further herein. The degree to which the implant 300 can becompressed (e.g., circumferentially, radially inwardly, etc.) may dependon one or more factors, properties, characteristics and/or otherconsiderations of the first portion 302, such as, for example, implantsize, water content, ingredients and other components, strength,elasticity, surrounding temperature, method of manufacturing, and/or thelike. Although described herein as generally rigid, the second portion304 and the third portion 306 may also have some degree ofcompressibility. Radial compression of an implant 300 can affect theoverall height, the shape and/or contours of outer surfaces (e.g., topor articulating surface, base or bottom surface, sides, etc.), and/orone or more other properties or characteristics of the implant 300. Insome embodiments, radial compression of an implant 300 causes the heightof the implant 300 to increase (e.g., relative to the height of theimplant 300 when not radially compressed). Consequently, carefulconsideration may be given to the design of the implant 300 based on,among other things, the expected level of radial compression that mayoccur once the implant 300 has been properly secured in the hole 310,prior to implantation. Otherwise, in some embodiments, uponimplantation, an implant 300 may not properly align with adjacentcartilage or other tissue surfaces in a joint or other anatomicallocation.

According to some embodiments, the implant 300 is loaded into a deliverysystem 312; only the distal end of the delivery system 312 isillustrated in FIG. 3A. The delivery system 312 can comprise an outerbody 314 and a plunger or pusher member 316. The outer body 314 may becylindrical or may taper radially inwardly towards the distal end of thedelivery system 312. In the illustrated embodiment, the plunger 316abuts the first portion 302 of the implant 300. The delivery system 312can be aligned with the hole 310, and then a user such as a surgeon candepress the plunger 316. The plunger 316 is translatable along thelongitudinal axis of the delivery system 312 to push the implant 300 outof the distal end of the delivery system 312 into the hole 310.Depression of the plunger 316 and/or deployment of the implant 300 maybe manual, mechanically assisted, combinations thereof, and the like.

FIG. 3B illustrates the implant 300 in the bone portion 308. The hole310 preferably has a depth that is greater than or equal to the heightof the second portion 304 and the third portion 306 such that the partof the implant 300 prolapsing from the bone portion 308, theload-bearing surface, comprises hydrogel and is free or substantiallyfree of the relatively more rigid porous material. In some embodiments,an upper surface of the implant 300 is about 1 millimeter (mm) to about3 mm above an upper surface of the bone portion 308 (e.g., the bone ofthe bone portion, remaining cartilage, etc.), also termed “proud,”designated in FIG. 3B by the measurement p, which can provide a desiredcontour of the damaged joint surface. In some embodiments, such a raisedor otherwise protruding configuration can assist in creating a smoothertransition between the exposed surface of the implant 300 and adjacentnative surfaces.

The first portion 302 may have a larger lateral dimension (e.g.,diameter) than the third portion 306 to create a “mushroom” shape, asillustrated in FIG. 3B, as well as in FIGS. 1A-2 and other examplesherein. In some embodiments, for any of the implants disclosed herein, aratio of a lateral dimension (e.g., diameter) and/or cross-sectionalarea of the first portion 302 or a portion thereof to a lateraldimension (e.g., diameter) and/or cross-sectional area of the thirdportion 306 or a portion thereof is between about 1 and about 1.3 (e.g.,greater than or equal to about 1.05, about 1.06, about 1.07, about 1.08,about 1.09, about 1.1, about 1.11, about 1.12, about 1.13, about 1.14,about 1.15, about 1.16, about 1.17, about 1.18, about 1.19, about 1.2,about 1.21, about 1.22, about 1.23, about 1.24, about 1.25, about 1.26,about 1.27, about 1.28, about 1.29, about 1.3, ranges between suchvalues, etc.). In other embodiments, the ratio is between about 1 and1.05 (e.g., greater than or equal to about 1.01, about 1.02, about 1.03,about 1.04, about 1.05, ranges between such values, etc.), or greaterthan about 1.3 (e.g., greater than or equal to about 1.3, about 1.35,about 1.4, about 1.45, about 1.5, about 1.55, about 1.6, etc.), asdesired or required.

The smaller third portion 306 can slide into the hole 310 of the boneportion 308, although preferably making contact with the sidewalls orperimeter of the hole 310, and the larger first portion 302 can bewedged into the hole 310 of the bone portion 308 due to its flexibility.Referring again to FIG. 3A, the implant 300 may be held in the deliverysystem 312 by radial compression of the implant 300. The substantiallyrigid porous material of the second portion 304 and the third portion306 might not be susceptible to radial compression. The larger firstportion 302 can be radially compressed or wedged into the outer body 314due to its flexibility while the smaller third portion 306 may slidewithin the outer body 314.

FIG. 3C schematically illustrates an example method of positioning theexample implant 150 of FIG. 1B. The implant 150 in a bone portion 358,for example by the method of FIGS. 3A and 3B or another method. Thethird portion 156 makes contact with the perimeter of the hole in thebone portion 358. The hydrogel material of the second portion andusually the first portion 152 is radially compressed in the hole in thebone portion 358. FIG. 3C illustrates a radially compressed segment 366and an uncompressed segment 368. The uncompressed segment 368 is overthe surface of the bone portion 358. Referring again to FIG. 3B, thesegment of the first portion 302 that is proud may be radially largerthan the segment of the first portion 302 that is in the hole 310 in thebone portion 308.

FIG. 4 schematically illustrates an example method of manufacturingexample implants 400. A mold 408 comprises a plurality of wells orcavities or recesses or holes 410. Bottoms of the wells 410 may becontoured, for example for a specific anatomy location in which animplant 400 will be placed, and/or other factors or considerations. Forexample, an implant 400 can be configured to generally or specificallymatch the slopes, contours, and/or other features of the existingcartilaginous and/or bone tissue (e.g., planar (e.g., flat), non-planar(e.g., curved, concave, convex, undulating, fluted)), a recess or holeor cavity created in the bone, and/or the like. Accordingly, thefunction of a rehabilitated joint or other targeted anatomical regionbeing treated can be improved. The bottom surfaces of the implants 400in the mold 408 will be the upper load bearing surfaces of the implants400 in use. In some embodiments, the mold 408 further comprises aplurality of anchors 412 configured to inhibit or prevent third portions406 from sinking into first portions 402 during the manufacturingprocess. The anchors 412 may comprise wire, clamps, releasable adhesive,combinations thereof, and the like. Hydrogel material of the firstportion 402 fills pores of the porous material of the third portion 406in the second portion 404. The upper surface of the hydrogel may begenerally planar, although other shapes are also possible. A moldconfigured to make one implant 400 at a time is also possible.

FIGS. 5A-5C schematically illustrate an example method of manufacturingexample implants 500. As shown in FIG. 5A, in some embodiments, a firstmold portion 508 comprises a plurality of wells or cavities or recessesor holes 510. The first mold portion 508 may be the same or differentthan the mold 408. In contrast to the method of FIG. 4 , the implants400 are made “upside down” in that the bottom surfaces of the implants500 in the mold 508 will not be the upper load bearing surfaces of theimplants 500 in use. Porous material 505, for example in the shape ofdiscs, grommets, etc., are inserted into the wells 510. Since the porousmaterial 505 are substantially rigid, they will not conform to anycontours at bottoms of the wells 510. The fit of the porous ceramic 505in the mold 508 is preferably tight enough that hydrogel materialsubsequently inserted into the wells 510 is inhibited or prevented fromflowing to bottoms of the wells 510.

As shown in FIG. 5B, a second mold portion 512 comprises a plurality ofwells 514 configured to be aligned with the plurality of wells 510 ofthe first mold portion 508. Bottoms of the wells 514 (or tops of thewells 514 in the orientation of FIG. 5B) may be contoured, for examplefor a specific anatomical location in which an implant 500 will beplaced, and/or other factors or considerations. For example, an implant500 can be configured to generally or specifically match the slopes,contours, and/or other features of the existing cartilaginous and/orbone tissue (e.g., planar (e.g., flat), non-planar (e.g., curved,concave, convex, undulating, fluted)), a recess or hole or cavitycreated in the bone, and/or the like. The upper surfaces of the implants500 will be the upper load bearing surfaces of the implants 500 in use.

As shown in FIG. 5C, the second mold portion 512 is aligned with thefirst mold portion 508. Hydrogel material can then be inserted into thewells 510, 512, for example through closable port or holes or apertures516. The hydrogel material fills some but preferably not all of thepores of the porous material 505. Porous material 505 free orsubstantially free of hydrogel material form the third portions 506,porous material 505 having pores at least partially filled or filled byhydrogel material form the second portions 504, and hydrogel materialfree or substantially free of porous material 505 form the firstportions 502.

The first mold portion 508 and the second mold portion 512 meet atintersection 518. Similar to blow molding processes, any spacing betweenthe mold portions 508, 512 may result in flashing. The molds 508, 512may be configured to reduce or minimize flashing, for example by beingprecisely corresponding, tightly joined, etc. The molds 508, 512 may beconfigured to not reduce flashing, for example by using a flash removalprocess or by allowing the implants 500 to have flashing.

One or more of the mold portions described with respect to FIGS. 4 and5A-5C, and modifications thereof, may be tailored to, or designed orcustomized for, a specific subject's anatomy. For example, a surface ofa bone and/or an opposing bone may be scanned (e.g., via computerizedtomography (CT), computerized axial tomography (CAT), positron emissiontomography (PET), magnetic resonance imaging (MRI), combinationsthereof, etc.), which can be used to make a mold (e.g., via 3D printing,CAD-CAM milling, etc.) to match specific anatomical features of aspecific patient or subject. For example, with reference to FIG. 4 , thebottom of the well 410 may be customized such that hydrogel of the firstportion 402 takes a certain shape. For another example, with referenceto FIGS. 5A-5C, the bottom of the well 514 may be customized such thathydrogel of the first portion 402 takes a certain shape. Other parts ofthe molds may also be modified (e.g., sides of the wells 410, 514, wells510, etc.). A custom implant can be advantageous, for example, when theanatomy has been damaged or otherwise includes unique characteristics.

In some embodiments, a scan may reveal that a plurality of implants maybe used for treatment. For example, compared to one implant, a pluralityof implants may be better able to treat a large defect, be betterprovide a load bearing surface to key points, and/or provide betteraccess to a physician. The scan can be used to select locations and/orsizes for a plurality of implants. For example, taking a knee joint asan example, a user may select in a scan a portion of a lateral condylefor a first implant and a portion of a medial condyle for a secondimplant. If the implant would provide an advantage if the portion is alittle more anterior, a little more posterior, a little more medial, alittle more lateral, etc., the implant can be customized to thatparticular location using the scan, which may result in, for example,different load bearing surface features, different dimensions, differentprotrusion amounts, combinations thereof, and the like.

Any of the implant embodiments disclosed herein, or equivalents thereof,can be manufactured using freeze/thaw cycling and/or any otherappropriate production method. For example, a hydrogel formulationcomprising water, saline, PVA (and/or other hydrogel materials), otherpolymeric materials, other additives and/or the like can be cooled,heated, and/or otherwise treated as part of a freeze/thaw manufacturingprocess. In some embodiments, a hydrogel solution comprising saline andabout 40% PVA by weight is heated to approximately 121° C. underelevated pressure conditions (e.g., to effect dissolution of thepolymer). For example, such a solution can be autoclaved to facilitatecomplete or substantially complete dissolution of the PVA in the saline,water, and/or other liquid. Next, the temperature and/or pressure of thesolution can be lowered to permit entrapped air and/or other gases toescape. In some embodiments, after the autoclaving or similar step, thesolution is generally maintained at a temperature of approximately 95°C. and atmospheric pressure for a predetermined time period. Thesolution can then be transferred (e.g., pumped, poured, etc.) into amold or mold portions (e.g., as described with respect to FIGS. 4 and5C) where, once set, form at least part of the shape of the implant.

The molded implant can be removed either after initial formation orafter undergoing additional treatment (e.g., freeze/thaw cycling, otherheat and/or pressure treatment, etc.). The molded implant may optionallybe cut, altered, or otherwise processed after molding. In someembodiments, flashing may be excised and discarded as part of asubsequent reshaping step.

In some embodiments, due in part to the remaining production steps,accommodation of any changes in size (e.g., expansion, contraction,etc.) that may occur or are likely to occur to the implant can beconsidered during manufacturing by properly sizing and otherwisedesigning the mold or mold portions. The amount of contraction orexpansion of the implant can be based on one or more factors orconditions, such as, for example, the number of freeze/thaw cycles, thetemperature and/or pressure ranges associated with the remaining steps,and/or the like.

Other methods can also be used to form the implants described herein.For example, an implant can be formed, at least in part, using aninjection molding process and/or any other molding or casting procedure.In such injection or transfer molding techniques, once the hydrogel orother implant solution has been prepared, it can be loaded into aninjection cylinder or other container of a molding press. The solutioncan then be forcibly transferred into a closed mold assembly using apneumatic or hydraulic ram or any other electromechanical device,system, or method. In some embodiments, the hydrogel and/or othersolution or implant component is injected into a corresponding closedmold assembly through a standard runner and gate system. Injectionmolding of implants can provide one or more benefits relative to openmold assemblies. For instance, an implant formed as part of an injectionmolding technique may be or may essentially be in a final shapeimmediately after the injection molding step has been completed suchthat the manufacturing process may be free or may be substantially freeof steps such as post-mold cutting, reshaping, resizing, and/orprocessing.

Regardless of how the implant is molded or otherwise shaped ormanufactured, the implant can be subsequently subjected to one or morefreeze/thaw cycles, as desired or required. In some embodiments, theimplant, while in a cavity of a mold, is cooled using a total of fourfreeze/thaw cycles in which the temperature is sequentially variedbetween about −20° C. and about 20° C. In some embodiments, the numberof freeze/thaw cycles, the temperature fluctuation, and/or other detailscan be different than disclosed herein, in accordance with a specificproduction protocol and/or implant design.

Following freeze/thaw cycling, the implant can be at least partiallyremoved (e.g., including fully removed) from the mold and placed in oneor more saline and/or other fluid (e.g., other liquid) baths where theimplant can be subjected to additional cooling and/or other treatmentprocedures (e.g., to further stabilize the physical properties of theimplant). In some embodiments, the implant undergoes an additional eightfreeze/thaw cycles while in saline. In some embodiments, such follow-upcooling procedures can be either different (e.g., more or fewerfreeze/thaw cycles, different type of bath, etc.) or altogethereliminated from the production process, as desired or required.

When the cooling (e.g., freeze/thaw cycling) and/or other manufacturingprocesses have been completed, the implants can be inspected for anymanufacturing flaws or other defects. At least some of the implants canbe subjected to selective testing for physical and othercharacteristics, in accordance with the original design goals and/ortarget parameters. The implant may be cut or otherwise processed toremove any excess portions (e.g., flash). In some embodiments, one ormore completed implant is packaged in hermetically sealed plastic traysor other containers comprising foil or other types of lids or coveringmembers. A volume of saline and/or other liquid can be included withinsuch trays or other containers to provide hydration of the implant(s)during storage and/or any other steps preceding use. In someembodiments, the implant tray or other container is terminallysterilized using e-beam exposure between about 25 kilogray (kGy) andabout 40 kGy.

Additional details related to implants comprising hydrogels, includingmethods of manufacturing and use, can be found in U.S. Pat. Nos.5,981,826, 6,231,605, and PCT Patent Application Publication No. WO2012/162552, each of which is hereby incorporated by reference in itsentirety for all purposes.

FIG. 6 schematically illustrates another example implant 600. Similar tothe implant 100, the implant 600 comprises a first hydrogel portion 602,a second overlap portion 604, and a third porous portion (e.g.,comprising porous material) 606. In some embodiments, the implant 600comprises an outer contour or rim or flange 608. As described withrespect to FIG. 5C, the use of a two-part mold may result in flashingwhere the mold portions 508, 512 meet at intersection 518. The outercontour 608 may comprise unremoved flashing. The outer contour 608 mayincrease apposition of the first portion 602 in a hole, which can helpto anchor the implant 600 in the hole.

FIG. 7A schematically illustrates an example implant 700. Similar to theimplant 100, the implant 700 comprises a first hydrogel portion 702, asecond overlap portion 704, and a third porous portion (e.g., comprisingporous material) 706. The implant 700 comprises outer sidewalls havingan angle to the longitudinal axis of the implant 700. In someembodiments, the implant 700 comprises a frustoconical shape. In someembodiments, the implant 700 comprises a pyramid shape. In someembodiments, the porous material in the second portion 704 and the thirdportion 706 comprises a disc shape, for example as described withrespect to the implant 100. In some embodiments, the porous material inthe second portion 704 and the third portion 706 comprises afrustoconical or pyramid shape, for example as shown in FIG. 7A. Theshape of the porous material and the shape of the hydrogel may be thesame (e.g., as illustrated in FIG. 7A) or different (e.g., comprising adisc-shaped porous material).

Implant dimensions, shapes, angles, tooling used to make non-cylindricalbone apertures, tooling to deploy non-cylindrical implants, potentialadvantages, etc. may be the same as or similar to (e.g., includingappropriate modification to include porous material as understood fromthe present application) the hydrogel implants comprising wedge shapesare described in U.S. Pat. No. 9,155,543, which is hereby incorporatedby reference in its entirety for all purposes.

In some embodiments, the porous material may be selected based on boneinfiltration characteristics and/or dimensions of the third portion 706.In certain such embodiments, the height and/or shape of the secondportion 704 may be at least partially based on a porosity of the porousmaterial. For example, if the porous material is more porous, thenhydrogel infiltration into the porous material will be greater, so lessporous material may be used. Conversely, if the porous material is lessporous, then hydrogel infiltration into the porous material will beless, so more porous material may be used.

FIG. 7B schematically illustrates an example method of positioning anexample implant 700. More specifically, FIG. 7B illustrates the implant700 in a bone portion 708. According to some embodiments, the boneportion 708 in which the implant 700 will be positioned has been drilledto form a hole or aperture or recess or cavity or crater or pit orpocket 710. The hole 710 comprises a shape corresponding to the shape ofthe implant 700. For example, the hole 710 may be frustoconical,pyramidal, etc. As described in further detail in U.S. Pat. No.9,155,543, a cylindrical pilot hole may be formed in the bone segment,then a secondary tool may be used to shape the hole 710 such that thehole 710 can take a wide variety of shapes. In some embodiments, thelateral dimension (e.g., diameter) of the top of the hole 710 is greaterthan the lateral dimension (e.g., diameter) of the bottom of the thirdportion 706, which is rigid. In some embodiments, a lateral dimensionand/or cross-sectional area of the top of the hole 710 is about 5% toabout 15% (e.g., about 5%, about 6%, about 7%, about 8%, about 9%, about10%, about 11%, about 12%, about 13%, about 14%, about 15%, rangesbetween such values, etc.) wider or otherwise larger than the lateraldimension and/or cross-sectional area of the bottom of the third portion706. The lateral dimension (e.g., diameter) of the hole 710 may besmaller than the lateral dimension (e.g., diameter) of the bottom of thefirst portion 702, which may flex radially inwardly. In someembodiments, a lateral dimension and/or cross-sectional area of the topof the hole 710 is about 5% to about 15% (e.g., about 5%, about 6%,about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about13%, about 14%, about 15%, ranges between such values, etc.) narrower orotherwise smaller than the lateral dimension and/or cross-sectional areaof the bottom of the first portion 702. The hole 710 may be coated orotherwise treated prior to positioning of the implant 700.

The hole 710 preferably has a depth that is greater than or equal to theheight of the second portion 704 and the third portion 706 such that thepart of the implant 700 prolapsing from the bone portion 708, theload-bearing surface, comprises hydrogel and is free or substantiallyfree of the relatively more rigid porous material. In some embodiments,an upper surface of the implant 700 is about 1 millimeter (mm) to about7 mm above an upper surface of the bone portion 708 (e.g., the bone ofthe bone portion, remaining cartilage, etc.), which can provide adesired contour of the damaged joint surface. In some embodiments, sucha raised or otherwise protruding configuration can assist in creating asmoother transition between the exposed surface of the implant 700 andadjacent native surfaces.

As a result of the shape of the implant 700 and the correspondingimplant site (e.g., in the hole 710), the implant 700 may be inwardlyradially compressed in order to insert the implant 700 in the hole 710.A delivery system or introducer and/or other delivery tools can be usedto facilitate positioning of the implant 700. Radially inwardcompressive forces may facilitate delivery of the implant 700 that is atradially oversized relative to the top of the hole 710. The degree towhich the implant 700 can be compressed (e.g., circumferentially,radially inwardly, etc.) may depend on one or more factors, properties,characteristics and/or other considerations of the first portion 702,such as, for example, implant size, water content, ingredients and othercomponents, strength, elasticity, surrounding temperature, method ofmanufacturing, and/or the like. Although described herein as generallyrigid, the second portion 704 and the third portion 706 may also havesome degree of compressibility. Radial compression of an implant 700 canaffect the overall height, the shape and/or contours of outer surfaces(e.g., top or articulating surface, base or bottom surface, sides,etc.), and/or one or more other properties or characteristics of theimplant 700. In some embodiments, radial compression of an implant 700causes the height of the implant 700 to increase (e.g., relative to theheight of the implant 700 when not radially compressed). Consequently,careful consideration may be given to the design of the implant 700based on, among other things, the expected level of radial compressionthat may occur once the implant 700 has been properly secured in thehole 710, prior to implantation. Otherwise, in some embodiments, uponimplantation, an implant 700 may not properly align with adjacentcartilage or other tissue surfaces in a joint or other anatomicallocation.

Interaction between the sidewalls of the hole 710 and the edges of theimplant 700 can create a downward force, which can create a more secureimplantation (e.g., resisting dislodge forces). Interaction between thesidewalls of the hole 710 and the edges of the implant 700 can create adownward force, which can help the third portion 706 make contact withthe bottom of the hole 710, which can improve bone infiltration into thethird portion 706.

In some embodiments, the third portion and the hole may have non-uniformlateral cross-sections. For example, the bottom of the third portion mayhave an ellipse shape having a length greater than a width, and the topof the hole may have an oval shape having a length greater than a width.During implantation, the implant may be positioned such that the lengthand width of the third portion are aligned with the length and width ofthe hole. The generally rigid third portion may fit through the holewhen aligned, but the generally rigid third portion may not fit throughthe hole when the implant is rotated. For example, after rotation, thelength of the third portion may not be able to fit through a width ofthe hole. If the length of an ellipse compared to a circle in a thirdportion for an otherwise same implant may increase the area of contactbetween the bottom of the third portion and the bottom of the hole byabout 10% to about 50% (e.g., about 10%, about 20%, about 30%, about40%, about 50%, ranges between such values, etc.). In some embodiments,the implant may be rotated until sides of the third portion make contactwith the hole. Contact between sides of the third portion and sides ofthe hole may provide increased area for bone infiltration and/orincrease downward force.

FIG. 7C schematically illustrates an example method of positioning anexample implant 720. Similar to the implant 700, the implant 720comprises a first hydrogel portion 722, a second overlap portion 724,and a third porous portion (e.g., comprising porous material) 726. Theimplant 700 further comprises an anchor 728. The anchor 728 isillustrated as comprising barbs, but implants comprising other types ofanchors compatible with the implant 720 and other implants (e.g., theimplants 100, 150, 180, 200, 300, 600, 700, and modifications thereof)are described in further detail herein. For example, the porous materialmay comprise a grommet shape including an eyelet. The eyelet may be in acenter of the porous material or elsewhere, including superficialeyelets in lateral sides of the porous material. The anchor may extendthrough the eyelet. The porous material may comprise a plurality ofeyelets, which may be used for a plurality of anchors and/or forsecuring a single anchor.

When the implant 720 is inserted into a hole 740 in a bone segment 732that comprises a secondary hole 742, the anchor 728 can fit into thesecondary hole 742. The anchor 728 can flex inwardly during insertionand then is resistant to retraction. The anchor 728 can maintain adownward force on the third portion 726 against the bottom of the hole740. The force may be advantageous at least until bone infiltration,which may be complete enough to anchor the implant without the anchor728 in about six to eight weeks. In some embodiments, the secondary hole742 can be formed while forming a pilot hole (e.g., using a dualdiameter drill bit). In some embodiments, the secondary hole 742 can beformed before or after forming a pilot hole (e.g., using a differentdrill bit), before or after forming a shape such as a wedge. In someembodiments in which a guide pin is used for procedures like drill bitalignment, the secondary hole 742 may be a result of removal of theguide pin.

FIG. 8A schematically illustrates an example implant 800. Similar to theimplant 100, the implant 800 comprises a first hydrogel portion 802, asecond overlap portion 804, and a third porous portion (e.g., comprisingporous material) 806. As illustrated in FIG. 8A, the porous materialcomprises a titanium mesh and/or stainless steel wool comprising abundle of intertwined filaments. The implant 800 comprises a mushroomshape in which the first portion 802 and the second portion 804 aregenerally hemispherical or dome shaped and the third portion 806 isgenerally cylindrical. The shape of the porous material in the secondportion 802 and the shape of the hydrogel may be the same (e.g., asillustrated in FIG. 8A) or different (e.g., the porous materialcontinuing as a cylinder, being disc shaped in the second portion 804,etc.). In some embodiments, the shape of the first portion 802corresponds to a load bearing surface, for example a condyle.

FIG. 8B schematically illustrates an example method of positioning anexample implant 800. More specifically, FIG. 8B illustrates the implant800 in a bone portion 808. According to some embodiments, the boneportion 808 in which the implant 800 will be positioned has been drilledto form a hole or aperture or recess or cavity or crater or pit orpocket 810. The hole 810 comprises a shape corresponding to the shape ofthe implant 800. For example, the hole 810 may comprise a generallycylindrical lower portion and a wedge shape or spherical segment shapeupper portion. As described in further detail in U.S. Pat. No.9,155,543, a cylindrical pilot hole may be formed in the bone segment,then a secondary tool may be used to shape the hole 810 such that thehole 810 can take a wide variety of shapes. In some embodiments, thelateral dimension (e.g., diameter) of the top of the hole 810 is greaterthan the lateral dimension (e.g., diameter) of the bottom of the secondportion 804, which is relatively rigid. In some embodiments, a lateraldimension and/or cross-sectional area of the top of the hole 810 isabout 5% to about 15% (e.g., about 5%, about 6%, about 7%, about 8%,about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about15%, ranges between such values, etc.) wider or otherwise larger thanthe lateral dimension and/or cross-sectional area of the bottom of thesecond portion 804. The lateral dimension (e.g., diameter) of the hole810 may be smaller than the lateral dimension (e.g., diameter) of thebottom of the first portion 802, which may flex radially inwardly. Insome embodiments, a lateral dimension and/or cross-sectional area of thetop of the hole 810 is about 5% to about 15% (e.g., about 5%, about 6%,about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about13%, about 14%, about 15%, ranges between such values, etc.) narrower orotherwise smaller than the lateral dimension and/or cross-sectional areaof the bottom of the first portion 802. In some embodiments, the lateraldimension (e.g., diameter) of the lower segment of the hole 810 is aboutthe same (e.g., about ±5%, about ±10%, about ±15%, about ±20%, about±25%) as the lateral dimension (e.g., diameter) of the third portion806, which is generally rigid but may be flexible or compressible enoughto squeeze radially inwardly. In some embodiments, as the third portion806 is longitudinally compressed, a lateral dimension (e.g., diameter)of the third portion 806 may increase. The hole 810 may be coated orotherwise treated prior to positioning of the implant 800.

The hole 810 preferably has a depth that is greater than or equal to theheight of the second portion 804 and the third portion 806 such that thepart of the implant 800 prolapsing from the bone portion 808, theload-bearing surface, comprises hydrogel and is free or substantiallyfree of the relatively more rigid porous material. In some embodiments,an upper surface of the implant 800 is about 1 millimeter (mm) to about7 mm above an upper surface of the bone portion 808 (e.g., the bone ofthe bone portion, remaining cartilage, etc.), which can provide adesired contour of the damaged joint surface. In some embodiments, sucha raised or otherwise protruding configuration can assist in creating asmoother transition between the exposed surface of the implant 800 andadjacent native surfaces.

As a result of the shape of the implant 800 and the correspondingimplant site (e.g., in the hole 810), the implant 800 may be inwardlyradially compressed in order to insert the implant 800 in the hole 810.A delivery system or introducer and/or other delivery tools can be usedto facilitate positioning of the implant 800. Radially inwardcompressive forces may facilitate delivery of the implant 800 that is atradially oversized relative to the top of the hole 810. The degree towhich the implant 800 can be compressed (e.g., circumferentially,radially inwardly, etc.) may depend on one or more factors, properties,characteristics and/or other considerations of the first portion 802,such as, for example, implant size, water content, ingredients and othercomponents, strength, elasticity, surrounding temperature, method ofmanufacturing, and/or the like. Although described herein as generallyrigid, the second portion 804 and the third portion 806 may also havesome degree of compressibility. Radial compression of an implant 800 canaffect the overall height, the shape and/or contours of outer surfaces(e.g., top or articulating surface, base or bottom surface, sides,etc.), and/or one or more other properties or characteristics of theimplant 800. In some embodiments, radial compression of an implant 800causes the height of the implant 800 to increase (e.g., relative to theheight of the implant 800 when not radially compressed). Consequently,careful consideration may be given to the design of the implant 800based on, among other things, the expected level of radial compressionthat may occur once the implant 800 has been properly secured in thehole 810, prior to implantation. Otherwise, in some embodiments, uponimplantation, an implant 800 may not properly align with adjacentcartilage or other tissue surfaces in a joint or other anatomicallocation.

Interaction between the sidewalls of the hole 810 and the edges of theimplant 810 can create a downward force, which can create a more secureimplantation (e.g., resisting dislodge forces). Interaction between thesidewalls of the hole 810 and the edges of the implant 800 can create adownward force, which can help the third portion 806 make contact withthe bottom of the hole 810, which can improve bone infiltration into thethird portion 806. The sides of the third portion 806 may appose thesidewalls of the lower segment of the hole 810 and contact the bottom ofthe hole 810, which can provide a large area for bone infiltration.

FIG. 8C schematically illustrates an example method of positioning anexample implant 800. In contrast to FIG. 8B, the hole 820 in the bonesegment 818 is generally cylindrical throughout. The bottom of the firstportion 802 can appose sidewalls of the hole 818. The hole 820 may beeasier and/or faster to form than the hole 810 such that the hole 820may be desired even if sidewall apposition by the third portion 806 isreduced or eliminated and Interaction between the sidewalls of the hole810 and the edges of the implant 810 do not create a downward force. Insome embodiments, a hole comprises a lower cylindrical portion having afirst lateral dimension (e.g., diameter) sized to correspond to alateral dimension (e.g., diameter) of the third portion 806 and an uppercylindrical portion having a second lateral dimension (e.g., diameter)larger than the first lateral dimension, which may be easier to formthan the hole 810 and still provide sidewall apposition by the thirdportion 806.

FIG. 9A is a side view of an example implant 900. FIG. 9B is across-sectional view of the implant 900 of FIG. 9A. FIGS. 9C and 9D aretop and side perspective exploded views of the implant 900 of FIG. 9A.Like several of the implants described herein, the implant 900comprises, in a first part 901, hydrogel 902 and porous material 904.The hydrogel 902 may infiltrate pores of the porous material 904. Asbest seen in FIGS. 9B and 9D, the porous material 904 is generallyannular. In some embodiments, the porous material 904 could be a soliddisc (e.g., like the porous material of the implant 100).

The implant 900 also comprises a second part 908. The second part 908comprises an annular rim, a bottom, and a barb 910. The rim and thebottom at least partially define a cavity configured to receive thefirst part 901. In some embodiments, the barb 910 is monolithic (formedfrom a single piece of material) with the remainder of the second part908. In some embodiments, the barb 910 is formed separately from theremainder of the second part 908 and coupled to the remainder of thesecond part 908. The second part 908 may comprise a rigid material suchas metal, ceramic, plastic, etc. The second part 908 may be formed, forexample, by metal casting, injection molding, milling, printing,combinations thereof, etc.

The barb 908 may be inwardly compressible when longitudinally advanced,for example into a hole in a bone site, but configured to catch whenlongitudinally retracted, for example from a hole in a bone site. Thesecond part 908 may comprise a porous material (e.g., to allow boneinfiltration) and/or non-porous material (e.g., the second part 908being anchored by the barb 908).

The second part 908 may be inserted at an implant site (e.g., a hole ina bone site) and the first part 901 may be inserted into the second part908, and thus also into the implant site. As best seen in FIGS. 9B-9D,the porous material 904 comprises an annular groove 905 and the secondpart 908 comprises a detent 912. When the first part 901 is insertedinto the second part 908, the porous material 904 and/or the detent 912can flex until the detent 912 interacts with the groove 905, at whichpoint the first part 901 is inhibited from being dislodged from thesecond portion 908. The groove 905 may be partially or fully annular. Insome embodiments, the second part 908 comprises a plurality of detents912 (e.g., two detents, three detents, four detents, five detents, sixdetents, ranges therebetween, or more than six detents). Thecircumferential spacing between detents 912 may be the same (e.g.,spaced by about 360° divided by the number of detents) or may varybetween pairs of detents 912.

FIG. 9E is a cross-sectional view of an example implant 920. The implant920 shares some features with the implant 900, for example comprisinghydrogel 922, porous material 924, and a second part 928. The secondpart 928 comprises a barb 930 comprising two radially outwardprotrusions, which may provide better dislodge resistance than a singlebarb. Converse to the implant 900, in which the porous material 904comprises a groove 905 and the second part 908 comprises a detent 912,in the implant 920, the porous material 924 comprises a detent 925 andthe second part 928 comprises a groove 932. The groove 925 may bepartially or fully annular. In some embodiments, the porous material 924comprises a plurality of detents 925 (e.g., two detents, three detents,four detents, five detents, six detents, ranges therebetween, or morethan six detents). The circumferential spacing between detents 925 maybe the same (e.g., spaced by about 360° divided by the number ofdetents) or may vary between pairs of detents 925.

FIG. 10A is a side view of an example implant 1000. FIG. 10B is across-sectional view of the implant 1000 of FIG. 10A. FIGS. 10C-10E aretop and side perspective exploded views of the implant 1000 of FIG. 10A.Like the implant 900, the implant 1000 comprises, in a first part 1001,hydrogel 1002 and porous material 1004. The hydrogel 1002 may infiltratepores of the porous material 1004. As best seen in FIGS. 10B and 10E,the porous material 1004 is generally annular. In some embodiments, theporous material 1004 could be a solid disc (e.g., like the porousmaterial of the implant 100).

The implant 1000 also comprises a second part 1008. The second part 1008comprises an annular rim, a bottom, and an anchor 1010. The rim and thebottom at least partially define a cavity configured to receive thefirst part 1001. The second part 1008 may comprise a rigid material suchas metal, ceramic, plastic, etc. The second part 1008 may be formed, forexample, by metal casting, injection molding, milling, printing,combinations thereof, etc. The second part 1008 may comprise a porousmaterial (e.g., to allow bone infiltration) and/or non-porous material(e.g., the second part 1008 being anchored by the barb 1008).

The anchor 1010 comprises an insert 1022 and radially outwardlyextending fingers 1024. The anchor 1010 may be coupled to the secondpart 1008 by a wire 1026 extending through holes 1009 and forming a knot1028. The anchor 1010 may be pushed into a hole (e.g., a hole in a bonesite). The fingers 1024 may flex radially inwardly during advancementinto the hole and flex radially outward to inhibit dislodgement from thehole. Ends of the wire 1026 may optionally form a loop. When ends of thewire 1026 are pulled, the knot 1028 tightens to draw the second part1008 and the anchor 1010 closer together. The anchor 1010 is inhibitedfrom retracting, so the tightening pushes the second part 1008 into thehole. In some embodiments, the anchor 1010 shares features with theanchors described in U.S. Patent Pub. No. 2015/0351815, which isincorporated herein by reference in its entirety for all purposes.

The second part 1008 may be inserted at an implant site (e.g., a hole ina bone site) and tightened, and the first part 1001 may be inserted intothe second part 1008, and thus also into the implant site. As best seenin FIGS. 10B-10E, the porous material 1004 comprises an annular groove1005 and the second part 1008 comprises a detent 1012. When the firstpart 1001 is inserted into the second part 1008, the porous material1004 and/or the detent 1012 can flex until the detent 1012 interactswith the groove 1005, at which point the first part 1001 is inhibitedfrom being dislodged from the second portion 1008. The groove 1005 maybe partially or fully annular. In some embodiments, the second part 1008comprises a plurality of detents 1012 (e.g., two detents, three detents,four detents, five detents, six detents, ranges therebetween, or morethan six detents). The circumferential spacing between detents 1012 maybe the same (e.g., spaced by about 360° divided by the number ofdetents) or may vary between pairs of detents 1012.

FIG. 10F is a cross-sectional view of an example implant 1040. Theimplant 1040 shares some features with the implant 1000, for examplecomprising hydrogel 1042, porous material 1044, and a second part 1048.The second part 1048 comprises an anchor 1050 including a loop 1060proximal to a knot 1058. Converse to the implant 1000, in which theporous material 1004 comprises a groove 1005 and the second part 1008comprises a detent 1012, in the implant 1040, the porous material 1044comprises a detent 1045 and the second part 1048 comprises a groove1052. The groove 1052 may be partially or fully annular. In someembodiments, the porous material 1044 comprises a plurality of detents1045 (e.g., two detents, three detents, four detents, five detents, sixdetents, ranges therebetween, or more than six detents). Thecircumferential spacing between detents 1045 may be the same (e.g.,spaced by about 360° divided by the number of detents) or may varybetween pairs of detents 1045.

FIG. 11A is a side view of an example implant 1100. FIG. 11B is across-sectional view of the implant 1100 of FIG. 11A. FIG. 11C is a topand side perspective view of the implant 1100 of FIG. 11A. FIG. 11D is atop and side perspective exploded view of the implant 1100 of FIG. 11ALike the implant 900, the implant 1100 comprises, in a first part 1101,hydrogel 1102 and porous material 1104. The hydrogel 1102 may infiltratepores of the porous material 1104. As best seen in FIGS. 11B and 11D,the porous material 1104 is generally annular. In some embodiments, theporous material 1104 could be a solid disc (e.g., like the porousmaterial of the implant 100).

The implant 1100 also comprises a second part 1108. The second part 1108comprises an annular rim and a bottom. The rim and the bottom at leastpartially define a cavity configured to receive the first part 1101. Thesecond part 1108 may comprise a rigid material such as metal, ceramic,plastic, etc. The second part 1108 may be formed, for example, by metalcasting, injection molding, milling, printing, combinations thereof,etc. The second part 1108 may comprise a porous material (e.g., to allowbone infiltration) and/or non-porous material (e.g., the second part1108 being anchored by the barb 1108).

The bottom of the second part 1108 comprises a plurality of holes 1109configured to receive screws 1110. In some embodiments, the bottom ofthe second part 1108 comprises one hole 1109, two holes 1109, threeholes 1109, four holes 1109 (e.g., as shown in FIG. 11D), five holes1109, six holes 1109, ranges therebetween, or more than six holes.

The second part 1108 may be inserted at an implant site (e.g., a hole ina bone site). One or more screws 1010 may be inserted through holes 1109to tighten the second part 1108 against the hole. The first part 1101may be inserted into the second part 1108, and thus also into theimplant site. As best seen in FIGS. 11B and 11D, the porous material1104 comprises an annular groove 1105 and the second part 1108 comprisesa detent 1112. When the first part 1101 is inserted into the second part1108, the porous material 1104 and/or the detent 1112 can flex until thedetent 1112 interacts with the groove 1105, at which point the firstpart 1101 is inhibited from being dislodged from the second portion1108. The groove 1105 may be partially or fully annular. In someembodiments, the second part 1108 comprises a plurality of detents 1112(e.g., two detents, three detents, four detents, five detents, sixdetents, ranges therebetween, or more than six detents). Thecircumferential spacing between detents 1112 may be the same (e.g.,spaced by about 360° divided by the number of detents) or may varybetween pairs of detents 1112.

FIG. 11E is a cross-sectional view of an example implant 1120. Theimplant 1120 shares some features with the implant 1100, for examplecomprising hydrogel 1122, porous material 1124, and a second part 1128.Like the implant 1100, the second part 1128 comprises a bottom includingholes configured to receive screws 1110 therethrough. The second part1128 also comprises holes in the sidewalls configured to receive screws1140 therethrough. Inserting the screws 1140 in the sidewalls of thesecond part can provide more options for fixation of the second part1128 at an implant site and/or better fixation than a second partcomprising only bottom holes. Converse to the implant 1100, in which theporous material 1104 comprises a groove 1105 and the second part 1108comprises a detent 1112, in the implant 1120, the porous material 1124comprises a detent 1125 and the second part 1128 comprises a groove1132. The groove 1132 may be partially or fully annular. In someembodiments, the porous material 1124 comprises a plurality of detents1125 (e.g., two detents, three detents, four detents, five detents, sixdetents, ranges therebetween, or more than six detents). Thecircumferential spacing between detents 1125 may be the same (e.g.,spaced by about 360° divided by the number of detents) or may varybetween pairs of detents 1115.

FIG. 12A is a side cross-sectional view of an example implant 1200. Likethe implant 900, the implant 1200 comprises hydrogel 1202 and porousmaterial 1204. The hydrogel 1202 may infiltrate pores of the porousmaterial 1204. The porous material 1204 is generally annular. In someembodiments, the porous material 1204 could be a solid disc (e.g., likethe porous material of the implant 100). The porous material 1204comprises a detent 1206 configured to interact with or “bite” thehydrogel 1202. The detent 1206 may be partially or fully annular. Insome embodiments, the porous material 1204 comprises a plurality ofdetents 1206, for example at a variety of positions along the innerwalls of the porous material 1204. In some embodiments, the porousmaterial 1204 may comprise a non-porous material, for example becausethe bite of the detent 1206 provides sufficient interaction with thehydrogel 1202 to inhibit dislodgement of the hydrogel 1202. The porousmaterial 1204 further comprises a barb 1208. The barb 1208 may beinwardly compressible (e.g., due to being thin and/or porous) whenlongitudinally advanced, for example into a hole in a bone site, butconfigured to catch when longitudinally retracted, for example from ahole in a bone site. The barb 1208 may be partially or completelyannular. The porous material 1204 may comprise barbs 1208 at differentlongitudinal positions. In some embodiments, the porous material 1204may be 3D printed, machined, etc.

The height of the porous material 1204 may be at least partially basedon the intended use of the implant 1200. For example, if the intendeduse is a small joint (e.g., in a hand or foot), a larger profile and aless proud hydrogel 1202 generally reduces the chances of dislocation.

FIG. 12B is a side cross-sectional view of an example implant 1210. Likethe implant 1200, the implant 1210 comprises hydrogel 1212 and porousmaterial 1214 comprising a barb 1218. The porous material 1214 comprisesa groove into which the hydrogel 1212 can radially outwardly extend toform a detent 1216 or a flange if fully annular. The interaction betweenthe detent 1216 and the porous material 1214 provides sufficient bitethat the porous material 1214 may comprise a non-porous material.Depending on the mold, desirability of the detent 1216 extendingradially outward of the porous material 1214, etc., the detent 1216 maybe trimmed.

FIG. 12C is a side cross-sectional view of an example implant 1220. Likethe implant 1200, the implant 1220 comprises hydrogel 1222 and porousmaterial 1224 comprising a detent 1226. The porous material 1224 lacksor is free of a barb, but the porous material 1224 may interact withsidewalls of a hole at an implant site to allow bone infiltration. Theimplant 1220 may comprise a hydrogel detent like the implant 1210. Anyof the implants 1200, 1210, 1220 may comprise porous material detents,hydrogel detents, or combinations thereof.

FIG. 12D is a side cross-sectional view of example implants 1230, 1240.The implant 1230 comprises hydrogel 1232 and porous material 1234. Thehydrogel 1232 infiltrates the pores of the porous material 1234. Theporous material 1234 comprises a detent 1236 configured to engage agroove, for example in a second part and/or in a bone hole at an implantsite. The porous material 1234 has a height h₁. The hydrogel 1232 isproud over the porous material 1234. The implant 1240 comprises hydrogel1242 and porous material 1244. The hydrogel 1242 infiltrates the poresof the porous material 1244. The porous material 1244 comprises a detent1246 configured to engage a groove, for example in a second part and/orin a bone hole at an implant site. The porous material 1244 has a heighth₂ less than the height h₁. The hydrogel 1242 is proud over the porousmaterial 1244. The implant 1240 may provide more hydrogel 1242 to apposesidewalls of a second part and/or a bone hole at an implant site. If thebone stock and/or density is limited, the height of the porous materialmay be increased, which can provide column strength in the implant. Ifbone stock and/or density is favorable, the height of the porousmaterial may be reduced, which can allow more hydrogel apposition ofsidewalls.

With respect to any of the implants described herein in which the porousmaterial comprises metal, the implant may advantageously be visibleunder x-ray.

With respect to any of the implants described herein, comprising porousmaterial allowing fixation due to bone infiltration and/or comprising afixation device such as a barb, anchor, screw, etc., an overall heightcan be reduced versus and implant, for example, consisting essentiallyof hydrogel (e.g., lacking porous material and/or a fixation device),which generally uses interaction between a long bone hole and a largeheight to provide anti-dislodging force. In some embodiments, ananchored implant can have a height that is less than a height of anequivalent but unanchored implant by about 10% to about 60% (e.g., about10%, about 20%, about 30%, about 40%, about 50%, about 60%, rangesbetween such values, etc.). For example, if a hydrogel implant has adiameter of 10 mm and a height of 10 mm, then an implant as describedherein may have a diameter of 10 mm and a height of 5 mm such that theheight is 50% less.

FIG. 13A is a top and side perspective view of an example implant 1300.The implant 1300 comprises hydrogel 1302 and porous material 1304. Thehydrogel 1302 infiltrates pores of the porous material 1304. The porousmaterial 1304 comprises radially outward and upward extending fingers1306. Similar to the anchor 1010 of the implant 1000 described herein,the fingers 1306 may flex radially inwardly during advancement of theimplant 1300 into a bone hole at an implant site and flex radiallyoutward to inhibit dislodgement from the hole. In some embodiments, thefingers 1306 and general structure of the device 1300 share featureswith the anchors described in U.S. Patent Pub. No. 2015/0351815. Thehydrogel 1302 may extend radially outward towards the fingers 1306.

FIG. 13B is plan view of an example device 1310 for manufacturingexample implants such as the implant 1300. In some embodiments, thedevice 1310 comprises a hydrogel mold. The device 1310 comprises aplurality of radially outwardly extending arms 1312 configured toaccommodate hydrogel that can infiltrate cutouts forming the fingers1306. For example, with reference to FIGS. 4-5C and 13A, a porousmaterial 1304 comprising a plurality of fingers 1306 can be placed intothe device 1310. The device 1310 may be filled with hydrogel 1302, whichcan infiltrate pores of the porous material 1304 to form the implant1300.

Although several embodiments and examples are disclosed herein, thepresent application extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses of the variousinventions and modifications, and/or equivalents thereof. It is alsocontemplated that various combinations or subcombinations of thespecific features and aspects of the embodiments may be made and stillfall within the scope of the inventions. Accordingly, various featuresand aspects of the disclosed embodiments can be combined with orsubstituted for one another in order to form varying modes of thedisclosed inventions. Thus, the scope of the various inventionsdisclosed herein should not be limited by any particular embodimentsdescribed above. While the embodiments disclosed herein are susceptibleto various modifications, and alternative forms, specific examplesthereof have been shown in the drawings and are described in detailherein. However, the inventions of the present application are notlimited to the particular forms or methods disclosed, but, to thecontrary, cover all modifications, equivalents, and alternatives fallingwithin the spirit and scope of the various embodiments described and theappended claims. Further, the disclosure herein of any particularfeature, aspect, method, property, characteristic, quality, attribute,element and/or the like in connection with an implementation orembodiment can be used in all other implementations or embodiments setforth herein.

In any methods disclosed herein, the acts or operations can be performedin any suitable sequence and are not necessarily limited to anyparticular disclosed sequence and not be performed in the order recited.Various operations can be described as multiple discrete operations inturn, in a manner that can be helpful in understanding certainembodiments; however, the order of description should not be construedto imply that these operations are order dependent. Additionally, anystructures described herein can be embodied as integrated components oras separate components. For purposes of comparing various embodiments,certain aspects and advantages of these embodiments are described. Notnecessarily all such aspects or advantages are achieved by anyparticular embodiment. Thus, for example, embodiments can be carried outin a manner that achieves or optimizes one advantage or group ofadvantages without necessarily achieving other advantages or groups ofadvantages.

The methods disclosed herein include certain actions taken by apractitioner; however, they can also include any third-party instructionof those actions, either expressly or by implication. For example,actions such as “deploying an implant” include “instructing deploymentof an implant.” The ranges disclosed herein also encompass any and alloverlap, sub-ranges, and combinations thereof. Language such as “up to,”“at least,” “greater than,” “less than,” “between,” and the likeincludes the number recited. Numbers preceded by a term such as “about”or “approximately” include the recited numbers and should be interpretedbased on the circumstances (e.g., as accurate as reasonably possibleunder the circumstances, for example ±5%, ±10%, ±15%, etc.). Forexample, “about 1 mm” includes “1 mm.” Phrases preceded by a term suchas “substantially” include the recited phrase and should be interpretedbased on the circumstances (e.g., as much as reasonably possible underthe circumstances). For example, “substantially rigid” includes “rigid”and “substantially parallel” includes “parallel.”

What is claimed is:
 1. An implant configured for implantation in a bonesegment, the implant comprising: a first part that includes a hydrogelportion and a porous material portion; and a second part comprising anannular rim and a bottom that at least partially define a cavityconfigured to receive the porous material portion of the first part, anda barb extending from the bottom of the second part in a direction awayfrom the cavity, wherein when the implant is implanted in the bonesegment, the barb engages a hole formed in the bone segment to securethe implant.
 2. The implant of claim 1, wherein the porous materialportion has a generally annular configuration that surrounds a portionof the hydrogel portion.
 3. The implant of claim 1, wherein the porousmaterial portion is a solid disc.
 4. The implant of claim 1, wherein thehydrogel is in pores of the porous material portion.
 5. The implant ofclaim 1, wherein the barb and the second part are formed as a monolithicstructure.
 6. The implant of claim 1, wherein the barb is formedseparately from remainder of the second part and is coupled to theremainder of the second part.
 7. The implant of claim 1, wherein thesecond part is formed of a rigid material.
 8. The implant of claim 1,wherein the barb is inwardly compressible when longitudinally advancedinto the hole in the bone segment but configured to catch whenlongitudinally retracted from the hole in the bone segment.
 9. Theimplant of claim 1, wherein the second part comprises a porous material.10. The implant of claim 1, wherein the porous material portioncomprises an annular groove and the cavity in the second part comprisesat least one corresponding detent for engaging the annular groove whenthe porous material portion is received into the cavity.
 11. The implantof claim 1, wherein the groove is partially or fully annular.
 12. Theimplant of claim 10, wherein the second part comprises a plurality ofdetents.
 13. The implant of claim 1, wherein the porous material portioncomprises at least one detent and the second part comprises acorresponding groove.
 14. The implant of claim 13, wherein he groove ispartially or fully annular.
 15. An implant configured for implantationin a bone segment, the implant comprising: a first part that includes ahydrogel portion and a porous material portion; and a second partcomprising an annular rim and a bottom that at least partially define acavity configured to receive the porous material portion of the firstpart, and an anchor coupled to the bottom of the second part oppositefrom the cavity, wherein when the implant is implanted in the bonesegment, the anchor engages a hole formed in the bone segment to securethe implant.
 16. The implant of claim 15, wherein the anchor comprisesan insert and radially outwardly extending fingers.
 17. The implant ofclaim 16, wherein when the anchor is pushed into the hole in the bonesegment, the fingers flex radially inwardly during advancement into thehole and flex radially outward to inhibit dislodgement from the hole.18. The implant of claim 15, wherein the bottom of the second partcomprises two or more holes and the anchor is coupled to the second partby a wire extending through holes in the bottom of the second part andforming a knot within the cavity of the second part, wherein the wireenables the second part and the anchor to be drawn closer together bypulling on ends of the wire from inside the cavity.